He 111 Bombing Sight problem

[Volker]

Hello all,

After testing He 111 bombing sight we found out that there is a problem and we can not target correctly.Please if you spot a mistake from our side comment because we can't figure it out.


The mission consists of 1 He 111 at 2000 m. and IAS of 270 km. flown by AI pilot and loaded with 8 SC 250 and high alt fuses.All 8 bombs selected to be dropped at once.

The target is just a cross shaped building array almost at shore to minimize altitude differences.Whether is clear and all winds tuned down to zero. (weather regarding we hope we set it correctly to zero in FMB any advice happily acceptable)

We did 4 bombing runs which are uploaded in the zip file named ascending 1_He111_Bombing_Run.trk, 2_He111_Bombing_Run.trk and so on.

The game is on Patch v 1.01.14550
The settings we used in each run are these:

Mis: 1_He111_Bombing_Run.trk
IAS set in sight as readed from instrument at 270 km.
ALT set in sight as readed from instrument at 2000 m.

Mis: 2_He111_Bombing_Run.trk
IAS set in sight from TAS list to 300 km. (2000 m. IAS 270km.->TAS 305km.)
ALT set in sight as readed from instrument to 2000 m.

Mis: 3_He111_Bombing_Run.trk
IAS set in sight as readed from instrument at 270 km.
ALT set to sight at 2100m. because we set air pressure in altimeter instrument to 1013 millibar. (by reference in usual conditions of air pressure , we don't know if it is exact)

Mis: 4_He111_Bombing_Run.trk
IAS set in sight from TAS list to 310 km.
ALT set in sight at 2100m.

Unfortunately none worked. Either the sight is bugged or we do a serious mistake which we can't figure out. We did the same runs as a full mission (take off,climb,flight to target etc.) with two people on board (pilot-bomber) and the results where the same.

So either the community must correct us or add this to future issues to be resolved in next patch.

Thank you for reading.Forgive my EG :)

[SG1_Lud]

Nice setup.

Can you define better: none worked?

I am watching the tracks as we speak, maybe there is the answer to my question.

[SG1_Lud]

Here my observations:

First of all, your test may indicate that the code is computing IAS instead as TAS as it should. That would be the only valid explanation of why when you use IAS, yo are closer to the target, and when you use TAS, the bombs are short to the target.

So yeah maybe this is a bug. Can you pass me the mission to do test myself. I would like to hear blackdog_kt, and T)(or opinion too about this.

OK, the rest of my observations:

* You were not releasing at the exact speed. I read 265 instead of 270 Km/h. 5 km/h could introduce several meters of error (bombs will impact before the intended point) so you have the bombardier has to take that in account when fixing the crosshairs over the target.
* You were not releasing at exactly 2.000 m, but 1975m. That introduces several meters more (accumulates to above error)
* Have you taken in account wind... if there was a north component of it, this would introduce a new error with the same effect than the above.

The first two, blame your pilot (lol).
AS for the wind, you cannot know, but then: dont use 0 m of distance in the bombs. If you are releasing 4 pairs, divide the total lenth of the target by 4 and maximize your chances of 1-2 hits, intead of trying to concentrate your fire.

Hope it helps

[Volker]

Thanks for observations,mission included at post end.

Oh, use our camera as recorded to see how off from the target bombs hit. Even when you think that they came close, the sight was targeting far off the spot.

(P.S. Irrelevant. Its a joy that we need a bomber/gunner human inside the plane now cause flying this bird is tasking :)

[SG1_Lud]

Thank you Volker.

Yeas , sorry I forgot to comment that. In the test I have done, the crosshair in the final moments drifts off, but I learned to "ignore that": if in the first seconds the thing is stable, I consider it a valid solution and forget the crosshair, because the thing (maybe realisticly?) doesn't fixates perfectly.

Maybe you can try with another human?. If you see me online (mi nick there is Lud, dont hesitate to ask, maybe we can have some fun and learn something)

[Blackdog_kt]

Haven't really seen much on the He111 because when i tried it i was still having performance issues with the sim, i didn't know the engine operating limits that well and broke my engines, plus i was also trying to figure out the course autopilot because i was doing it solo in offline mode.

What i can tell you though is that weird things seem to happen to the Blenheim too. While waiting for a hotfix to correct the prop pitch issue on the 109/110 i decided to fool around a bit in the Blenheim yesterday, so i started a free flight mission from the QMB with a load of four 250lb bombs and the detonator that's armed by default.

That mission spawns you near Dover, so i just went across the channel to bomb an airfield in Calais. I flew low, about 3000ft, which makes the IAS/TAS conversions almost non-existent. I kept my airspeed and altitude steady, input the values to the bombsight and had a go.

The bombs impacted and exploded just fine, but about halfway before the release point and the target.

That being said, this test is not really conclusive because i don't know if and how strong a wind exists in that mission. What i'm going to try next is make a "recon" run at tree top level to see the altitude of the Calais coast relative to sea level. I have a feeling that those cliffs could be as much as 500-1000ft high and this considerably throws off the aim, since we need to use altitude over the target in the bombsight and not mean sea level (MSL) altitude.

[SG1_Lud]

In my test in the He-111 I rapidly came to the conclussion that trying to bomb from the bombardier position and being accurate at the same time is highly difficult. Let alone making serious test while we don't have a way to release the bombs while looking thru' the sight. So it is not a comfortable secnery for testers, tos ay the least.

The way in tthat IL2 1046 calculated ballistics, as is known, wasn't taking in account the friction in the air, nor winds, unless you were modded. For that reason one could put the sight to 0 degrees and watch the bombs from release to impact, that is, the horizontal speed of the bombs was nearly constant.

But here we have new variables that affect the values we need for the equations:

Height of the plane (depends on altitude of the plane, altitude of the target) and altitude of the plane (depends on T,P)
TAS (depends on IAS, T, P)
and then GS (depends on TAS, wind)
bomb aerodynamics (depends on an aerodnynamic coeff.)

T: can be established for a test, using the planes that can measure outside temps
P: ? FMB?
wind: ? (dont know if it can be user-programmed in FMB)
bomb friction coeff: ?

Too much efforts for trying to reverse engineering the code, and give some quality observations to the devs. Furthermore, at the current state of the sim I think they have other priorities...


In the meantime, what I did is "learn" by trial and error to bomb from the pilot position. I noted several reference points in the down-view of the pilot for releasing at different altitudes. I use always the same setting in the engine, for a IAS of 250 km/h.

The sweet spot for the He-111 as per the manual (and I could confirm it is well done in the sim) are

Altitude: 3.000 m
IAS = 250 km/H
Corresponds to ATA = 1.0 and RPM = 2200, compressor stage II.

[T}{OR]

So yeah maybe this is a bug. Can you pass me the mission to do test myself. I would like to hear blackdog_kt, and T)(or opinion too about this.

OK, the rest of my observations:

* You were not releasing at the exact speed. I read 265 instead of 270 Km/h. 5 km/h could introduce several meters of error (bombs will impact before the intended point) so you have the bombardier has to take that in account when fixing the crosshairs over the target.
* You were not releasing at exactly 2.000 m, but 1975m. That introduces several meters more (accumulates to above error)
* Have you taken in account wind... if there was a north component of it, this would introduce a new error with the same effect than the above.

Since I still haven't got the game or the rig to play it on - I will only make short comments.

Speed is more important than the altitude. If you miss +/-100 meters you shouldn't miss the target. But if you don't get the speed right, you will over/under shoot the target.

One more thing - in old IL2 when using automated bombsight, the cross-hairs pointed out where the last pair of bombs will land. I don't know if this is the case with CloD.

I will be of more help when I get the game. :)

[Volker]

~cheyennepilot~
Thanks mate, if I found you in a server I ll ask u to join and fly a He111 nick is KG200_Volker :)
I forgot to mention for the mission, load it as a server, join blue force and pick the plane from the map to ENTER it as bombardier so the AI ,if you don't jump in pilots seat yourself, will fly to the target.

~Blackdog_kt~
Can't comment on Blenheim, no experience on it :( If you are interested for autopilot ask to give you in pm or a post here the way we use it.

~cheyennepilot~
Thank you for the info. We understand that there are new data to consider in regard to bombing with He111, that's why I ask for help here :)
For the wind part, you can open the mission in FMB and go to VIEW -> MISSION PARAMETERS and set winds/weather there, but I am not sure it works correct.

~T}{OR~
Get the game! It has problems yes, but I believe they ll fix them so everyone can enjoy its huge IMHO potential.
We can set the distance which we want the bombs to drop apart now and how many of them, e.g. set bombs 1 to 6 drop with 40 meters spread, but with current miss on targeting I can't tell if it calculates for 1st or last bomb :(

[SG1_Lud]

Volker, regarding your observations about IAS and TAS when programming the bombsight... are you by any chance flying with the option "realistic bombing" off?

[T}{OR]

~T}{OR~
Get the game! It has problems yes, but I believe they ll fix them so everyone can enjoy its huge IMHO potential.
We can set the distance which we want the bombs to drop apart now and how many of them, e.g. set bombs 1 to 6 drop with 40 meters spread, but with current miss on targeting I can't tell if it calculates for 1st or last bomb :(

I intend to. But first I need to get my rig assembled. :)

Waiting for the Bulldozer benchmarks next month before I pull the trigger.

[SG1_Lud]

Do you need any help?

We'll need the Level Bombing Manual v 3.0 soon ;)

[T}{OR]

Thanks, but no help needed except info how certain hardware behaves with CloD, but I already know that. I love building rigs on my own. :)

Right now I work and study as the same time, so even if I had a new rig I wouldn't be able to enjoy it. Soon... ;)

[Volker]

Settings are full real

[ATAG_Keller]

Digging up an old thread to re-address this issue.

Did an offline test tonight at 1000m and at 2000m.

Test 1: 1000m

In order to get the bombs to drop on target I had to do the following:

Set airspeed at TAS, 330km/h.
Set bombsight at 1300m (300m higher than actual)
Constantly keep the crosshairs on target by using the "adjust bombsight" commands until the bombs release.

Test 2: 2000m

Set airspeed at TAS, 320km/h.
Set bombsight at 3200m (1200m higher than actual)
Constantly keep the crosshairs on target by using the "adjust bombsight" commands until the bombs release.

One big observation that I had was, when dropping stings of multiple bombs (12x 50kg) the last bomb to hit the ground is the first bomb to detonate and the rest fall behind the first ones and detonate backwards and not forwards.

[ATAG_MajorBorris]

Beta tester of the month goes to...ATAG_Kelller:-)

[nakedsquirrel]

Was playing around with Keller and Jimbop's observations. Thought I'd throw the results on the bananna forms as well as our own:

There seems to be a ~1.6 ratio (coincidentally the same ratio between imperial and metric)

it's either

Altitude*1.6

or

Airspeed/1.6

You can use mode 22 for level bombing. The problem with mode 22 is that it seems to have trouble actually leveling out the plane, so you usually end up in a slight dive. I've found you can correct this with slight flaps adjustment. Drop the flaps a few degrees and you will be in level flight at a constant airspeed ready to drop! (Trim does not work in mode 22)

Also the plane seems to have a 1-degree slip to the left, or at least the bombs do, nudging the bomb sight 1 degree to the left will put your bombs on target with mode 22 enabled.

I prefer using altitude*1.6 to adjust the bombsight, you have more room to play with. It's ok if you are off by 100m in altitude, but if you are off by 10kph, you will miss.

The problem with this is that you can't really bomb higher than 3750m, because KPH/1.6 isn't accurate enough.

The only way I could find around this is by dividing both my altitude and IAS by a number and then multiplying my altitude by 1.6. So on my last run my altitude was 4500m and my airspeed was 270kph. so I divided them both by 1.5 and multiplied the altitude by 1.6, so my airspeed in the bomb sight was 180kph and my altitude was 4600m and my bombs landed on target.

I don't really advise bombing small targets from that high of an altitude. I could probably hit an airfield or a city block, but it's really hard to keep track of your airspeed, altitude, make all the calculations and constantly adjust the bomb sight all at the same time.

Piece of cake!